The background

I was intrigued when Garmin brought out their "High Sensitivity" version of the eTrex. It claimed to have improved sensitivity which would make it better at navigating in forests. This would be a huge advantage, since tree cover is the worst enemy of GPS navigation, causing loss of signal and inaccurate locations. Navigating in forests is difficult and an improved GPS would be a blessing. It is also cheap - which seems a double blessing.

The units compared

So, my wife bought me an eTrex "H" and I started to compare it with my Geko 201. The testing was low-key but very real. Quite simply, I put the two units side by side in the lid of my rucksack and took them both for walks, mainly in the flat Leicestershire countryside.

Now, after some 20 walks with the two units, about half the results are inconclusive. The Geko is winning the remainder by about a 2:1 margin!

How did I assess them?

I started the tests with an open mind, waiting to see how the comparison would develop. I was hoping to see the eTrex produce less scattered points when the route led near or through trees. Sadly I could see no sign of this.

I then started looking at how well the individual points plotted on a digital Ordnance Survey map. In particular, how far off the drawn paths the individual points were plotting. I got a shock when I realised that the Geko was, on average, outperforming the eTrex. Not what I anticipated!

Comment

The eTrex "H" is quicker to lock-on to the satellites than the Geko. It often claims an improved accuracy as-displayed in the viewing window of the GPS. But the Geko regularly out-performs the eTrex in accuracy.

Conclusion

"High Sensitivity" ≠ "High Accuracy"

I will persist a little longer in my comparison trials. But I will be surprised if the eTrex can stage a comeback from its present weak position. Given the choice, I suggest you get yourself a Geko!